Abstract: In a spark gap switch 12 of a pulse generating circuit 2 of a plasma generator T, an intermediate electrode 15, which is not connected to any electrical source, is disposed at a nearly middle position between a first spherical electrode 13 and a second spherical electrode 15 so as to hold respective spark gaps to the both spherical electrodes 13, 14. Further, in the spark gap switch 12, switching operation is performed between the both spherical electrodes 13, 14 by causing two-stage spark discharge in the first spark gap between the first spherical electrode 13 and the intermediate electrode 15, and in the second spark gap between the intermediate electrode 15 and the second spherical electrode 14. Thus, in the spark gap switch 12, pulse voltage of high voltage and high frequency is stably generated for a long time, and further the spark gap switch 12 may be made compact.

Abstract: A high voltage gap discharge switch is provided with a pair of sphere electrodes 1, projections 2 and a blower 5. The sphere electrodes 1 are separated by a discharge gap and oppose each other. The projections 2 are provided integrally at the mutually facing tips of the sphere electrodes 1, and have a projection length of 1/100 to 1/8 times the diameter of the sphere electrodes 1 and an outer diameter of 1/100 to 1/10 times. The blower 5 gives rise to an air current for expelling products produced on the projections 2 due to the generation of a spark discharge. The blower 5 supplies air to the discharge gap at a wind speed of 0.5 to 25 m/sec.-KW. One objective of the present invention is to stabilize the wave-form of a high voltage pulse and to increase its durability using a simple construction.

Abstract: In a method of corona discharge processing of resin formings surface, excellent corona discharge processing is possible, even if there is a distance between the resin formings and the discharge electrode, by generating a high voltage pulse having a pulse width of 1 .mu.s or more, an average electric field strength of 4 to 20 kv/cm denoted by applied voltage (wave height) versus interelectrode distance, and a pulse frequency of 10 pps or more. This processing is performed by the apparatus which comprises arranging a transfer conveyor to transfer the resin formings, a counter-electrode placed in a down side of the transfer conveyor, a dielectric to cover a surface of the counter-electrode, and a number of discharge electrodes which are arranged in a definite distance above the resin formings along the transfer route.

Abstract: A plasma generator including an excitation electrode and an opposite electrode confronting the excitation electrode such that plasma is generated upon impression of a high voltage between the excitation electrode and the opposite electrode. The plasma generator further includes granular material which is at least partially composed of dielectric grains and is provided between the excitation electrode and the opposite electrode.